Apparatus for forming glass beads on metallic elements



April 13, 1948. 2,439,437

APPARATUS FOR FORMING GLASS BEADS on METALL'IC ELEMENTS J. s. STULL Filed July 14, 1944 3 Sheets-Sheet 1 V Arrow/5X 4 April 13, 1948. J, 5, s-ru 2,439,437. Q

ARPARA'IUS FOR FORMING GLASS BEAES ON METALLIC ELEMENTS Filed July 14, 1944 3 Sheets-Sheet 2 24 176. 3 i 46 kg 25 54 4 will" E //V VE/V70f? J. 6'. STULL Arm/MA April 13, 1948.

s. STULL 2,439,437

APPARATUS FOR FORMING GLASS BEADS 0N METALLIC ELEMENTS Filed July 14, 1944 I 3 Sheets-Sheet 3 ATTORNEY Patented Apr. 13, 1948 V e 2.439;43'7 APPARATUS FOR FoRM'if N METALLIC ELE inst-fie ENTS} tip-primate Jiiij 14, 1944, sfiitrndi sa ijis" This invention relates toan' apparatus for forming glass on a. metal element and more particularly to an apparatus for molding a glass' head on the output lead of anelectronio tube.

In the manufacture of some electronic devices. it is essential that as nearlype'rfect alignment as possible be maintained between the central conduc'ting output lead of the device and its glass envelope. In the past, the practice has beento form the spacing element between the centralconductor and envelope by machining a globule or bead of glass, attached to the conductor, to the desired shape so that it"will space the'con ductor from the envelope. V V v It is an object of the present inventionto. provide a simple and veryf accurate apparatus for rapidly forming an article.

In accordance with one" embodiment of the invention, an apparatus is"p rovided: formolding a glass bead previously attached 'tothe'output lead of the electronic device wherein a Vertically reciprocable lead'supporting and guide post, having a central aperture therein for receiving the shank of thelead, is normally urged to a'positipn to receive the leadwith the glass bead attached thereto and maybe depressed tocarry the bead first into: the path of: heating flames to plasticize the glass bead and then to position itin a f ourpart die. In'the practice of the invention, an operator may manipulate'the lead guiding post to first carry it into position in the heating flames; whereupon, after-the glassbead has been heated, the operator compresses the bead'somewhat with a suitably shapedpair of pliers to facilitate the entrance of the bead into the molding die, unless the head has been previously so formed. The four parts of the die cooperate to provide a central aperture through which the lead may pass] its supporting guide post; After'the pOSt hasbeen lowered to permit the partially formed bead of glass to move down onto" the formin'g'dies; acon ducting plunger may be actuated to force the globule or head of glass down into the die, where it will be molded to the desired configuration. The four-part die is mounted for reciprocation with respect to a frusto-conical passage, with which the outer surfaces of the fourpart die cooperate, whereby, after the molding operation, the bead may be removed from the die by raising all four parts of the die simultaneously to cause them to move awayfrom each other by the camming-action of a cam coaxial with respect to the lead supportingguide post. As soonas the parts of the die are disengaged from the bead, the guide postwillmo've up to remove the bead from the die.

cdniiiiete-uiiderstandifig"at the invention may Hell by're'f re'iic'e t'g3the'fb1lowirigdetailed den conjunction with scri p tiori' v the accompanying d "'wings ;wlie1fein 5 Pi is a side eI View ofan apparatus g the fea thiini ention', some broke away to illustratefeatures of eievaedflarviw of the appa- *viw on an enlarged v "tag the line 3 -3 of the arrows; lan s ction-s taken sub- I a p 4, 5*f 5 an'd- 6-6, respectively; L n 13 in he direction of the arrows-and showf g det'ail of construction of the four-p die and ts actuating mechanisms; f' 1 sect'onal view takensubstantiall yjalong oiFig'. 3 in the direction of-the a 0 howing partofthe mechamsmiio'r movin tumour parts of the molding a itf. y

F g 8 i sj a' eta 'e'v'v n perspeotive of the i iifit eadfo ia i new fibah ne a e d or globuleotglas's a achedt formed "inthe v p 7 A Fi -1. 4 1e d w. .w.. h wm he; e d withltheglasbead"thereoifformd to thedesired shape;

r gs; wherein like ret- Yafi f th s ar s paiitlcular reference a1'1d 2; it will be noted d'upon a suitable aim frame, designated I I U l6; may be supported. The ni'aliniframefllfi 1 cutfaw ay asshown' at 14 to formap i-ofi-sid'e-m'einbers- H and Land ts fight" endIbaSe mate is. At

. elite?" erence characters ermio i t b p h w 'i i F 9 f the compacting plunger 25 has a socket 28 formed in it, as shown most clearly in Figs. 3 and '7, to receive the upper end of the output lead 21. The depth of the socket 28 will control the distance the lead extends beyond the bead. After an output lead 21 has had the globule or head 26 of glass attached to it, it may be inserted in the upper end of a supporting guide post 35, as shown most clearly in Figs. 3 and 7, in which there is a central bore or pocket 36 adapted to receive a reduced shank 31 of the output lead. The upper end of the post 35 slides in a cap member 38, which is threaded into a sleeve 39, in turn threadedly positioned in outwardly beyond the periphery of the support ymember .41 through a pair of slots 1| and 12 the base plate l9. The cap member 38 has a were tically extending passage 49 adapted to serve, as

of the post 35 is attached to a plunger 4|, carry-.

ing at its lower end a collar 42, pinned to the plunger 4| by means of a pin 48. The collar 42 has a handle 43 mounted on it whereby it may be manipulated. In addition to receiving the handle 43, the'collar 42 has the lower end of a contractile spring 44. fixed to it, the upper end of the spring being attached ,to a lock nut 45 threaded ontothe outer surface of the sleeve 39, thus to accurately position the sleeve 39 with re spect to the base plate l9. Due to the just described construction, the spring 44 normally urges the plunger 4| to move upwardly in the sleeve 39 and to -carry the supporting post 35 to a. position just above a burner supporting plate 46 suitably attached to the upper end of a tubular support member 41, which is,in turn, mounted on the base plate 19. .When ,the fpost 351s in its uppermost position and the spring 441s contracted,-t he upper surface-of the collar 42 will strike the lower end of the sleeve 39 thus to pos' ition the post 35 as shown in Fig. l, where it will be accessible to the operator so that; the operator may insert the shank 31 of the output lead 21 in the post.

Mounted upon the upper surface of the burner supporting plate 46 are a pair of burner supporting brackets 5 |*5 I, which support burners 5252 in position to project a flame against the glass bead 26'on an output lead whenthe plunger 4| is moved to the position shown in Fig. 2, thus to plasticize the glass bead suiiicie'ntly so that an operator may, by using apincers 'or pliers (not shown) compress? the bead of glass radially to permit its entrance into the molding dies to be described. In some instances, the head 26 may be preliminarily formedand this compression thereof will not be necessary. V

Also positioned ontheburner supporting plate are four burner supporting brackets 53-53, which are positioned to carry burners 54-54 in position to direct flames through ports 5555 formed in the support member 41 so that the flames will impinge upon die members 56, 51, 58 and 59 comprising parts of a four-part die, designated generally by the numeral 69. The four die members 56, 51, 58 and 59 cooperate to form an inverted substantially frusto-conicalassembly, the sloping sides of which, as shown at 6|, cooperate with a camming face 62 tocause the dies to move together when the dies are moved downwardly into the support member 41. Adjacent the area where the ports55 extend through the side walls of the support 7 member 41, an annular passage 63 is formed in the member to permit-the flames directed through the ports to heat the die members 56,51, 58 and 59 equally.

The lower ends of the die members 56, 51, 58 and 59, constituting the molding die 69, are milled out to form an annular groove 64, adapted to reformed in the support member 41 and the retainer plates 55 and .66 may be attached to the upper surface of the'actuating plate 69 by means of ma chine screws 13 threaded into the plates 65 and 66 and extending through slots 14-14 formed in the plate 69.

, By 'means of this construction, any movement imparted to the tubular member 10 will be transmitted to the die members 56, 51, 58 and 59 to move the die members upwardly or downwardly as afunit a nd when the die rnembers are moved downwardly, the lslojping, sides 62 of the support member 41 will cause the die members to be moved radially inwardly to the positions shown in Figs. 3 and 7. When the tubular member 19 is moved upwardly by mechanism to be described, the die members 56, 51, 59 and 59 will be caused to move radially outwardly to release them from the globule or bead 26 of glass which has been molded on the output lead 21, by means of an annular cam member 96 formed on the upper end of the cap member 38. This cammember 89 cooperates with camming surfaces- 8|,;82, 83 and84 .formed by milling out the lower ends of the die members 56, 51, 59 and 59, respectively.

The tubular member 19is'normally urged downwardly to the positions shown in Figs. 3 and 7 by a pair of contractile springs 85 and 86 attached to pins 81 and 88 mounted in the side plates I1 and I8, respectively. The springs 85 and 85 have their upper ends attached to a pair of posts 89 and 99, which are suitably attached to the tubular member 19 and which extend through slots 9! and 92 formed in the support member 41. Portions of the posts '89 and 99 will engage in notches 93 and 94 formed in a cam ring. 95'when the tubular member l0 is in its lowermost position, as shown in'Figs. 3and 7. The cam ring 95 is provided with a handle 96, whereby the ring may be rotated around the support member 41 which it encircles, thus to move the tubular member 19 to either of its two positions. When the cam ring 95 is in the position shown in Fig. 7, the tubular member 19 will be in its lowermost position and when the cam ring 95 is moved out of the position shown in Fig. 7, the tubular member 19 will be raised due to the camming action-between the surfaces of the notches 93 and 94 and the lower surfaces of the posts-89 and 99. t l c A better understanding of the. invention may be had by reference to the following brief description of the mode of operation of the apparatus. With the plunger 4| in its released or normal position, the post 35 will be in its uppermost position due to the spring 44 holding the collar 42 against the lower end of the sleeve 39 and in this position an operator may readily insert the shank 31 of the output lead 21 in the post 35. The globule of glass, in theform of a head 26, has, in a previous operation been applied to the output lead i1 and, upon proper manipulation of the handle 43, the bead of glass attached to the output lead maybe moved down into the flame projecting from the burner 52 and heated sufficiently to plasticize it, whereupon, the operator may, if necessary, manually compress the head 26 with any suitable forming tool so that the bead 26 will be flattened on its sides to facilitate its entrance into the die Bii. After the bead has thus been plasticized, the handle 33 may be moved downwardly to cause the bead the bead of glass to rest upon the upper surfaces of the die members 56, 57, 58 and b5 comprising the die 6&3. In some cases, the bead will drop into the dies and in others it will rest on the edges of the upper surfaces of the die. Immediately after the handle as has been moved to its lowermost position, the handle 22 may be operated to cause the plunger 25 to move downwardly and compact the giass in the die 56. Since the plunger 25 has the socket 28 formed in its lower end for receiving the upper extending end of the output lead 2?, the globule of glass will be formed in the shape shown in Fig. 9, a predetermined distance from the end of the lead 2'5, being maintained plastic by the heat transferred to it through the die members at, 51, 58 and 59, which are heated by the burners 54. After the globule of glass has been properly formed, the handle as may be manipulated to rotate the cam ring 95 and thus cam the tubular members '33 upwardly. As the tubular member iii moves upwardly, the plunger 25 having been raised to its upper position, as shown in Fig. 1, the die membars 53, El, 58 and as will more radially outwardly under the influence of the annular cam member acting on the camming surfaces shown at at to 86 on the respective die members, thus to release the dies from the glass and permit the spring id to move the output lead upwardly, carrying the properly formed bead of glass thereon up to the position shown in Fig. 1, whereupon the completed article may be removed from the apparatus by the operator.

What is claimed is:

1. In an apparatus for accurately forming a glass spacer element on the output lead of an electronic tube, means for supporting the output lead, means operable to move said supporting means, means surrounding said supporting means to guide it in its movement, a tubular member surrounding said guiding means and reciprocable with respect thereto, a support member surrounding said reciprocable tubular member, a plurality of die members having cam surfaces to engage the support member and supported jointly by said support member and by said tubular member, a cam member on said guiding means, other cam surfaces on the die members for cooperating with the cam member on the guiding means to effect the opening of said die members when the tubular member is moved in one direction, and cam surfaces on the support member for cooperation with the first mentioned cam surfaces on the die members to effect the closing of the die members when the tubular member is moved in the opposite direction.

2. In an apparatus for accurately forming -a glass spacer element on the output lead of an electronic tube, means for supporting the output lead, means operable to move said supporting means, means surrounding said supporting means to guide it in its movement, a tubular member surrounding said guiding means and reciprocable with respect thereto, a support member surrounding said reciprocable tubular memher, a plurality of die members having cam surfaces to engage the support member and supported jointly by said support member and by said tubular member, a cam member on said guiding mean other cam surfaces on the die members for cooperating with the cam member on the guiding means to efiect the opening of said die members when the tubular member is moved in one directionfcam surfaces on the support member for cooperation with the first mentioned cam surfaces on the die members to effect the closing of the die members when the tubular member is moved in the opposite direction, a chamber formed internally of the support member, and passageways in said support memher for directing a heating medium through the support member to the die members. a

3. In an apparatus for accurately forming a 'lass spacer element on the output lead of an ctronic tube, means for supporting the output ad, means for urging said supporting means to predetermined position, means surrounding said supporting means to guide it, a tubular member surrounding the guiding means and recioroca ale with respect thereto, a support mem- J surrounding said recipro-cable tubular member, a plurality of die members slidably supported iointiy by the support member and the member and having cam surfaces therea cam member on the guiding means, cam surfaces on the support member and cam memher for cooperation with the cam surfaces on the die members to effect the opening and closing of the die members upon reciprocation. of the tubular member, a chamber formed internally of the support member, passageways in the sup port member for directing a heating medium through the support member to the die member, a carnming ring rotatable around said support member, and means attached to the tubular support member and extending through the support member for actuation by said camming ring upon rotation thereof to move the tubular member. JOHN S. STULL.

REFERENCES CITED The following referencesare of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 614,843 Criggal Nov. 29, 1898 851,964 'Steimer Apr. 30,

1,789,014 Millar Jan. 13, 1931 2,195,483 Pranke Apr. 2, 1940 2,347,421 Little Apr. 25, 1944 

